Methamphetamine (meth) use is a growing problem nationwide that negatively impacts many aspects of a user's life. In Colorado, meth use is becoming a rapidly expanding social problem, as evidenced by rising treatment admission rates and an increase in seizures of clandestine labs. From a public health and scientific perspective, less attention has been paid to heterosexual meth users and their drug use and high risk sex behaviors, even though this population may face substantial risks for HIV. There is clearly a need to identify and test effective strategies to reduce meth use and HIV risk behaviors in heterosexuals. Major questions about the interaction of meth use and HIV risk behaviors, especially sex risk, remain unanswered. One important issue that we know little about is the implementation of an effective, evidence-based treatment strategy among out-of-treatment, street-recruited meth users and how that treatment impacts drug use and HIV risk behaviors. Novel approaches for the reduction of meth use and risk behaviors among an out-of-treatment population are needed. Contingency management (CM) has been found to be an effective strategy for reducing drug use among stimulant users in treatment including meth users and men who have sex with men (MSM) who use meth. Strengths-based case management (SBCM) focuses on client strengths as a means of addressing a broad array of life problems, which may then directly impact drug use and HIV risk. In this study, we will build on qualitative and quantitative pilot data that we collected through a NIDA-funded R21 that examined the context of sex risk behaviors among meth users and the feasibility of implementing CM and SBCM with this population. Building on what we learned, we propose to use structured interviews to compare three behavioral interventions in reducing meth use and HIV risk. Using randomized clinical trial (RCT) methods, 450 meth users will be recruited through street outreach in Denver and then randomly assigned to one of the following arms: no intervention (HIV testing and counseling only), Contingency Management (CM), or Contingency Management plus Strengths-Based Case Management (CM/SBCM). All clients will be offered HIV testing and counseling. Data will be collected at baseline and at 6 and 12 months. Primary outcome measures of this study include reduced meth use and HIV risk behaviors. A secondary outcome measure is improved mental health status. PUBLIC HEALTH RELEVANCE: Methamphetamine use is a large and growing problem nationwide. Treatment options for methamphetamine users are scarce and needed. This study will expand the options for treatment by examining the efficacy of different behavioral interventions on reducing methamphetamine use and HIV risk behaviors. This will then lead to improved health outcomes and reduced disease transmission.